I absolutely support same-sex marriage for the following reasons:
1) Marriage is not about gender or producing children. Marriage is about commitment. Gay and lesbian couples can be just as commited, if not more so, than heterosexual couples. Think about it. One can have heterosexual relations without committment, and one can even produce children without being committed to the other parent. What makes the difference? Why do some choose to marry? Because they are committed to their partner. One chooses to marry someone to whom they commit the remainder of their life.
2) Marriage is not a "God-based" arrangement, and did not begin with the culture which produced the writings which later were collected to form the Bible. People all over the world, even those who did not claim to be "Gods chosen people", were joining themselves together in committed relationships for thousands of years before the "thou shalt not" writings of the Biblical patriarchs. In many of these cultures, there was no bias against same-sex relationships.
3) "Gods" word does not condemn same-sex marriage, or for that matter, homosexuality. Rather, some nomadic fundamentalists chose to prohibit ALL sexual activity outside of certain narrowly defined parameters. These writings are not the words of God, or even a god. They are just the writings of men, who claimed to speak for God. The same thing happens today, with people and organizations such as Jerry Falwell, and with the Taliban. They make a claim to act in God's name, then cite some "inspired scripture" to justify their hateful actions.
4) Failure to provide full marriage benefits to same-sex couples is simply hate-based religious discrimination, directed against those who don't share the same religous beliefs. Laws which discriminate against those of a particular religious belief are unconstitutional.